Counterfeit-coin detecter



J. A. THOMPSON. Counterfeit Coin Detector.

No. 224,807. I Patented Feb. 24, I880.

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UNITED STATES PATENT OFFICE.

JOHN A. THOMPSON, OF CHICAGO, ILLINOIS.

COUNTERFElT-COIN DETECTER.

SPECIFICATION forming part of Letters Patent No. 224,807, dated February 24, 1880.

Application filed January 13, 1880.

To all whom it mag concern:

Be it known that I, JOHN A. THOMPSON, of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Counterfeit-Coin Detecters; and I hereby declare the following to be a full, clear, and exact description thereof, which will enable others skilled in the art to which my invention appertains to make and use the same, reference being had to the accompanying drawing, forming a part hereof,

and in which the figure represents a perspective view of a counterfeit-coin detecter embodying my improvements.

The object of my invention is to provide a device that will readily and surely detect counterfeit from genuine coin; and my invention consists in the construction of the device or detecter, as hereinafter described and claimed.

It is well known that when coin is made wholly or in part of base metal it is lighter than genuine coin of the same size, and if made of the same weight it must necessarily be thicker or larger in diameter than the genuine coin.

In the drawing, A represents a plate of sheet metal of known gage and weight, preferably of brass or German silver, and may be of any desired dimensions, and which is first stamped from a flat piece of metal, and its depending and tapering sides orflanges afterward formed as shown, so as to form the fulcrum for the plate.

In the center of the plate, and running from end to end, is a struck-up rib, a, which stiffens and strengthens the plate and divides it into two parts, one side of whichis adapted and marked for gold coin and the other for silver. On either side of the rib a is a series of slots or perforations, I), each of which is of the same width for about one-third of its length, and then gradually increasing in width, so as to form a tapering slot toward the fulcrum of the plate, said slots being of a width sufficient to receive and hold the coin of the desired denomination without allowing it to pass wholly through.

Each of the slots 1) is made wider at its end nearest the fulcrum of the plate, so as to readily receive the coin, while its other end is made of a width corresponding to the thickness of the coin, so that when a genuine coin is placed and held within the slot corresponding to its denomination it will cause. the plate to tip down over the fulcrum c nearest to such coin, the fulcrum 0 being previously adjusted for that purpose. If the coin is made thicker than and so as to correspond in weight with the genuine coin it will not pass within the desired slot to its proper place, and will, consequently, fail to tip the plate on its fulcrum.

It will be observed that the flanges (Z are made tapering from at or about their ful crums to their ends, and that the plate A is provided with two fulcrums, c, which are formed out of and as a part of the flanges d. The space 0 between the fulcrums 0 need not necessarily be cut out, and the notches f may be filed away (more or less) for the purpose of adjusting the fulcrums to the plate.

Having thus described my invention, what JOHN A. THOMPSON.

Witnesses:

WM. ZIMMERMAN, N. (Downs. 

